1. Field of the Invention
The present invention relates to an electronic timepiece including an analog time display unit for indicating time with hands and an electrooptic data display unit for displaying data.
2. Description of the Related Art
A combination wristwatch has recently been available. The combination wristwatch is a combination of a hand display type electronic wristwatch for displaying time with hands, to which a variety of functions, e.g., a function of displaying a date and a day of the week, an alarm function, and a stopwatch function, are added, and a liquid crystal data display unit for displaying these data.
In such a combination wristwatch, two display portions of an analog time display unit and an electrooptic data display unit are mounted side by side on a single surface of a case. In order to reduce the wristwatch in size at least one of the areas of the two display portions must be reduced. As a result, a display on a small area display portion becomes difficult to see. In contrast to this, if both the areas are increased to allow displays on the two display portions to be easily seen, the planar shape of the case of the wristwatch is increased in size.
Recently, in addition to the above-mentioned relatively simple functions, the above wristwatch is equipped with more sophisticated functions such as a telephone number storing function and a calculator function. For this reason, a large number of switches must be newly mounted on the case. This further increases the planar shape of the wristwatch case in size.
In a wristwatch with a calculator disclosed in U.S. Pat. No. 4,108,340, watch and calculator cases in which an analog display type watch and a calculator are respectively housed are fixed back to back, and a band is inserted in a through hole formed between the cases. The band can be freely reversed in the through hole. The two cases can be reversed on the band as needed so as to selectively set the analog watch or the calculator in the same direction as that of the surface of the band. In such a watch, the planar shape of the pair of cases can be reduced in size. However, the thickness of the pair of cases is increased. Although the time display portion of the analog watch can be increased in size, since the display portion of an electrooptic data display unit of the calculator and an operation portion of a switch unit are mounted side by side on a single surface, the data display portion is reduced in size, or the number of switch units which can be arranged is undesirably limited.
In a dual display watch disclosed in U.S. Pat. No. 4,444,513, a watch case is constituted by upper and lower half cases. An analog time display unit is arranged in the upper half case, whereas an electrooptic data display unit and a switch unit are arranged in the lower half case. The upper half case is coupled to the lower half case so as to be freely opened/closed. Similarly, in this watch, since the upper and lower half cases are stacked on each other, the thickness of the watch case is increased. Although the display portion of the analog time display unit can be increased in size, since the da&a display portion of the electrooptic data display unit and an operation portion of the switch unit are mounted on a signal surface of the lower half case, the data display portion must be reduced in size with an increase in number of switch units, or the number of switches which can be arranged is undesirably limited.
In the above-described two U.S. Patents, in order to increase the data display portion in size and increase switches .n number, the calculator case and the lower half case must be increased in size. As a result, the planar shape of the watch case is inevitably increased in size.